Downward Draining Herbs - Introduction to Chinese Herbology in TCM

Hey, this is Nicholas. Let's talk about downward-draining herbs. What do we mean by downward-draining? Well, these are herbs that promote movement in the large intestine and facilitate the expulsion of stool. This is just a fancy way of saying that they're laxatives. They make you poop. So, in what situations would we use these downward-draining herbs? Well, one obvious answer is constipation. If a person has difficult or infrequent bowel movements, we could use downward-draining herbs to facilitate the expulsion of stool and treat constipation. Another, maybe less obvious reason is, this is another way we can expel pathogenic influences from the body. So, like with herbs that release the exterior, we are promoting sweating to push the pathogen out through the surface with the sweat. Well, here, if we have something like interior heat, we can purge the large intestine and guide the heat out through the stool. So, the category of downward-draining herbs has three subcategories, and they're all very different. We have purgatives, moist laxatives, and harsh expellants. Purgatives strongly purge the large intestine to treat constipation and clear heat. They tend to be cold and bitter, and they have a strong downward action. Moist laxatives are moist, and they're laxative. These herbs gently lubricate the large intestine and are most suitable for treating long-standing constipation due to deficiency. They tend to be nuts or seeds, which are oily in nature, in order to lubricate the large intestine. As for their taste, they tend to be sweet in flavor, referring to their ability to moisten. Harsh expellants are harsh, and they expel. With these herbs, we're not actually treating constipation. These herbs are used for pathogenic water accumulating in the upper body, for things like pleurisy and ascites. For example, with gonsway, Fenske says, this is a violent, cathartic herb that causes one to pass water anally. So that's what we're talking about. We're quickly draining pathogenic water through the large intestine. So all of these categories are very different, and we need to make sure we match them to the patient's condition. Purgatives are for purging excess. They tend to have a quick effect, so we use them for excess conditions. But, because of their strong, bitter, downward nature, most of these herbs are contraindicated during pregnancy. Moist laxatives are much more gentle, so we're more likely to use them with weak patients, elderly patients, and patients with deficiency. But because we're gently lubricating the large intestine, they may take some time to work. With purgatives, if you take them at night, we might expect you to have a bowel movement the next morning. But with moist laxatives, you would be taking these herbs for days and weeks and expect to notice a gradual improvement over time. Harsh expellants are for more severe situations, and you might not see them used very much in modern practice. Most of these herbs are toxic, so they have a smaller dosage, and most of them are contraindicated during pregnancy. So let's look at the herbs from each of these categories. First is our purgative, da huang, ray radix at rhizoma. Da huang. Da huang is rhubarb root. Da huang purges the large intestine to treat constipation, and it also clears heat and drains fire. But these two actions kind of go together, because, again, it turns out that one of our strategies for clearing heat is to drain it out through the large intestine. At this point, it might be useful to review our Shang Han Moon theory. This was a theory of how cold pathogens penetrate through the six levels, tai yang, yang ming, xiao yang, tai yin, xiao yin, zhuo yin. So our first level is the tai yang level, and for that we have two types, excess and deficiency. For tai yang excess, we have fever and chills, no sweating, and a floating, tight pulse. And our herb for this one is ma huang. For tai yang deficiency, we have fever and chills with sweating, and a floating, weak pulse. Our herb here is gui zhi, cinnamon twig. Now, when we get to the yang ming level, the pathogen actually transforms from cold into heat. And here, we also have two types, but instead of excess and deficiency, it's yang ming channel disease and yang ming organ disease, or yang ming bowel disease. So yang ming channel disease presents with the four great symptoms, great fever, great sweat, great thirst and vexation, and a large, surging pulse. For this one, the herb we learned was shi gao, gypsum fibrosum. But for this category, the one we're interested in is the yang ming bowel pattern. Remember, the yang ming organs are the stomach and large intestine, so this is heat binding in the stomach and large intestine, presenting with symptoms like fever, abdominal pain that's worse with pressure, and constipation. The pulse is going to be deep, forceful, and rapid because we're dealing with a pattern of interior excess and heat. So for this yang ming bowel pattern, we're going to use da huang to purge the large intestine, treating the constipation and getting rid of the heat. So when we go back to the functions of da huang, we see that da huang clears heat and purges the large intestine to treat yang ming bowel disease. But besides just clearing yang ming heat, da huang can clear other types of heat as well. Da huang clears heat and cools the blood, especially when there's bleeding. Remember, heat can speed up the blood and cause it to move recklessly outside of the vessels. So da huang can stop bleeding due to heat, for things like hemorrhoids, blood in the stool, vomiting blood, and nosebleed. Also remember, to emphasize an herb's action of stopping bleeding, we can use it in its charred form. So to stop bleeding, we use charred da huang, called da huang tan. Da huang also clears damp heat for things like edema, jaundice, and Lynn syndrome. And then, another really important one, da huang strongly invigorates blood. In fact, the Chinese term used here is puo shui, which means to break the blood or crack the blood. So da huang doesn't just gently smooth out the flow of blood. Da huang cracks the blood and breaks right through stagnation. So it's especially useful for things like fixed sharp pain or abdominal masses. In fact, da huang is so good at invigorating blood that can be used externally in cases of injury and trauma. We have a formula called san huang san, which is nicknamed herbal ice because it's used externally for injury and trauma. So here, da huang is clearing heat to deal with redness and inflammation, and then it's invigorating blood to get rid of the stagnation. Some other things we can mention, da huang is nicknamed jun jian, or the general, because of its strong actions. It's cold, bitter, and has a strong downward action. And it also strongly invigorates blood. Both of these things make it contraindicated during pregnancy or with heavy menses. The literal translation of da huang is big yellow, because it's yellow. It can very easily stain things yellow, and if you take it internally, it can actually cause your sweat to turn yellow. So maybe you can remember that da huang is yellow, so it's good for jaundice, when your skin turns yellow, and difficult urination. Also, da huang is so strong and bitter, it can actually come out in the breast milk. It can turn the milk yellow, and cause diarrhea in the nursing infant. So da huang is contraindicated during breastfeeding. And the last thing we'll mention is the cooking instruction. For a strong purgative effect, da huang should be added during the end of the cooking process, cooking it only 3 to 5 minutes. For all other actions, da huang can be cooked a normal 30 minutes, and its purgative effect will be reduced. So remember, the prolonged cooking of da huang will reduce the purgative effect. If you want to purge the large intestine, add da huang during the last 3 to 5 minutes. So that was a lot of things. To briefly review, da huang purges the large intestine, treating constipation and heat bind, making it the representative herb for yang ming bowel disease. To emphasize this purgative effect, add da huang during the last 5 minutes of cooking. Da huang invigorates blood, or we can even say it breaks the blood. Because of its strong invigorating action, and because of its cold, bitter, downward direction, da huang is contraindicated during both pregnancy and breastfeeding. And then, da huang cools the blood, clears damp heat, and can be used in its charred form to stop bleeding. So that was da huang, our purgative herb. Next, we have moist laxatives. The herb we learned here is huo ma ren, cannabis semen. Huo ma ren. Huo means fire, ma means hemp, and ren means seed. So huo ma ren means fire hemp seed, or just hemp seed. And like we said, the reason we use seeds is because they contain oils which lubricate the large intestine to gently relieve constipation. So huo ma ren is especially useful for constipation and dry stools due to yin or blood deficiency. This can mean constipation after a febrile disease when heat has damaged the fluids, or this can mean chronic constipation in weak patients, elderly patients, or postpartum patients. In these situations, using cold, bitter herbs like da huang to purge the large intestine might be too strong and too draining. So instead, we use sweet, moistening herbs to gently relieve constipation. Huo ma ren also mildly tonifies yin, so it's good for constipation with yin deficiency. And huo ma ren can be used to treat sores and skin ulcers due to heat, either taken internally or applied topically. But for this function, huo ma ren is fairly mild, so it would only be used as a secondary herb. Huo ma ren is sweet because it moistens and tonifies yin. The dosage is larger than average, 9 to 15 grams. But the important thing to know, common to many seeds, huo ma ren should be crushed before adding it to the decoction. This is because huo ma ren has a hard shell, so if you don't crush it, you won't be able to extract the oils through that shell. So, if you want to be really traditional, you can use a mortar and pestle to crush huo ma ren, or if you're lazy like me, you can just pulse it a few times in a coffee grinder. Huo ma ren can have some toxic side effects, like nausea, vomiting, diarrhea, agitation, and confusion. But that's only if you take grossly excessive amounts of it. Hemp seeds have recently become trendy in western nutrition as a food supplement because they're high in omega-3 and omega-6 fatty acids, so it should be pretty safe to take in normal amounts. So that was our moist laxative, huo ma ren. And finally, we have our category of harsh expellants, or cathartics. Again, these herbs aren't for treating constipation. Rather, they're for driving pathogenic water out of the body, for things like pleurisy and ascites. Pleurisy is swelling in the chest around the lungs, and ascites is fluid accumulation in the abdomen, usually due to liver malfunction. The traditional term for this condition is drum distention. That is, the fluid accumulating in the abdomen makes you look like a barrel or a drum. So herbs in the category harsh expellants drive this pathogenic water out through the large intestine. The herb we learned is gansui, consway radix. Gansui. Like we said before, gansui is a violent, cathartic herb that causes one to pass water anally, so it treats severe fluid accumulation in the chest and abdomen. Gansui also drives out phlegm, for things like seizure due to wind phlegm or severe shin problems due to phlegm. Gansui enters the lung and kidney channels because those are the organs that have to do with water metabolism. And it enters the large intestine channel because we're draining that water through the large intestine. And the important thing to remember, gansui is toxic, so it has a smaller dosage, and it's contraindicated during pregnancy. And one last thing we can point out, you may remember at the very beginning we talked about the theory of how to combine herbs. We gave these different types of combinations fancy names, like mutual accentuation, mutual enhancement, mutual counteraction, blah blah blah. Well, one of our combinations was mutual incompatibility, or what we also call the 18 incompatible herbs. When we say two herbs are mutually incompatible, we mean that this combination will give rise to side effects that are not present in either herb alone. And therefore, this combination should be avoided. There are three sets of incompatible herbs for a total of 18. So here we see that gansui is on the list of herbs that are incompatible with gansau, or licorice root. In fact, three of the four herbs that are on this list come from the category harsh expellants. Now honestly, this might not ever come up in your clinical practice, but it is something that you like to ask on tests. So if you ever get a question about which herbs are incompatible with gansau, make sure you pick the answer with harsh expellants in it. So that's our category of downward-draining herbs. To summarize, purgatives tend to be cold and bitter. They purge the large intestine to clear heat and relieve constipation. The one we learned here was dahuang. Moist laxatives are sweet and moistening. They lubricate the large intestine to gently relieve constipation. They tend to be oily seeds like huomaren, cannabis semen. Harsh expellants are harsh, toxic herbs that drive out water accumulation through the large intestine. The one we learned was gansui. So that's it for today. If you want to learn more about Chinese herbs, you can check out the video for the next category, which is herbs that drain dampness. But I hope you enjoyed this one, because that's all for today. Thanks, and see you next time.